Fabric fire hose



Patented Nov. 27,

UNITED STATES PATENT OFFICE FABRIC FIRE HOSE James w. Stallings, mason Heights, N. J., as-

signor to Riihm & Haas Company, Philadelphia, 7 Pa a corporation of Delaware No Drawing. Application December 11, 1942,

' Serial No. 468,662

4 illalms.

.Durposes because it is extremely flexible, can be rolled fiat and thus easily packed and stored, and when in use maybecome wet enough, by diffusion through the fibers, to be fire-resistant. Heretofore, linen hose has had wide acceptance because the fibers swell on becoming wet, close the interstices between the. yarns, and thusprevent leakage when the water in the hose is under high pressure. On the other hand, ordinarycotton hose fails to swell sufficiently and thus permits water, for example, to pass freel through the interstices between the yams of the hose when the pressure exceeds a low maximum. In order to correct this, fault, it has been customary to line the cotton hose with rubber. when the hose is so lined, however, the water cannot diffuse through the walls to keep the exterior of the hose wet and thus render it fire-resistant.

This invention provides a method of treating a hose made of cellulosic fabric whereby the fibers become more water-receptive and swell in contact with water. Thus, for example, a cotton hose so treated acquires properties heretofore associated only with a linen hose, while treated linen hose acquires additional mter-receptivityand swells more rapidly than when untreated. .The cost of the cotton hose so improved is-less than that of the ordinary linen product. Furthermore, the rubber lining ordinarily used in the customary cotton hose may be eliminated.

The fibers of the hose treated by my process become more water-receptive and tend to swell on contact with water. This increased waterreceptivity is a newly appreciated property and is, for the most part, the opposite of water-resistance, which is usually sought. When fabrics are treated by the process of this invention and are then-broughtinto contact with water, the fibers swell and thereby close the pores, or interstices, in the fabric.

This method comprises treating the fabric hose in separate operations with acrylonitrile and with one whichdissolves in .Water and dissociates therein to yield a high concentration of hydroxyl ions; Such a solution is also identified herein as acaustic solution. .In the practice of this'invention by my pre ferred method, the hose is saturated first with acrylonitrile by soaking, dipping, etc. Excess may then be removed for convenience. The wet hose is thereafter subjected to theaction of a strong hydroxide in solution. The concentration of the hydroxide, the length of time during which the fibers are in contact therewith, and the temperature of the treating solution are allfac'tors which determine the results. After being subjected to the effect of the hydroxide, the hose is freed therefrom by squeezing, hydroextracting, or

equivalent operation followed bythorou'gh washing with water alone or with an acidified solution capable of'neutralizing the hydroxide.

Thisinvention depends on the treatment of the fabric hose with acrylonitrile and with a strong hydroxide in solution. While the preferred' method has been described, it is to be a solution of a strong hydroxide, and subseduent-' 1y removing the letter. A strong hydroxide is order.

understood that the procedure may be varied. For example, the acrylonltrile may. be in solution in a suitable'solvent. Likewise, ,the aorylonitrile may be passedor pumped through the hose and, thereafter, the solution of the strong hydroxide 'may be passed therethrough. After contact with the latter, the hose may be laid away for shorter or longer periods of time at chosen temperatures until the hose has acquired the desired properties, after which unused hydroxide may beremoved by passing dilute. acid and/or water through the hose. By this method the degree of penetration of the reagents into the hose may be regulated within limits. By, control of the treating conditions, the properties of the fibers on the inside of the hose may be altered, while those on the outside of the hose retain their normal properties. Although it is preferred to treat the hose first with. acrylonitrile and then with a strong hydroxide, treatment may be eflected in the reverse In such a case the results will depend upon such factors as the time and temperature of treatment with the acrylonitrile. In any event, the cellulo'sic fabric hose is treated inseparate steps with acrylonitrile and a solution of a strong hydroxide. y

. While this invention applies to hose/constructed of natural and regenerated cellulosic yarns in regenerated cellulose is affected more rapidly than natural fibers and, accordingly. milder conditions and concentrations of hydroxide are ordinarily employed in order to avoid dissolvin the regenerated cellulose.

Ashes been indicated, the extent of the hydroxide treatment, which follows the treatment with acrylonitrile in the preferred procedure, affects the final properties of the "treated fibers.

At room temperature, a concentration of-about to about 25% of sodium hydroxide, for example, and a contact or reaction time of from one to forty-eight hours have been found to be suitable when the hose is constructed of natural cellulosic fibers. The required contact time-will depend in part upon the thickness and construction of the hose. At higher temperatures, the rate of chemical reaction is increased and the time of contact may be reduced. When the hose contains regenerated cellulose, it is desirable to use hydroxide solutions of lower concentration in order to avoid excessive attack upon the regenerated cellulose; and, at room temperature, aconcentration of about 2% to 9% is ordinarily suitable for this purpose. Thus, the concentration of the solution of strong hydroxide may vary from about 2% to 25%, and the contact time may vary from one to forty-eight hours, or even more, depending upon the type of fabric, the temperature, and the thickness of the fabric.

It is unnecessary to raise the temperature of droxide treatment is carried out be varied.

While sodium hydroxide is preferred, in view of its low cost and general availability, other strong caustics, such as potassium hydroxide and quaternary ammonium hydroxides, may be used. 0

Butyl benzyl dimethyl ammonium hydroxide, tetraethyl ammonium hydroxide, tetramethyl ammonium hydroxide, benzyl trimethyl ammonium hydroxide, dibenzyl dimethyl ammonium hydroxide, and tetraethanol ammonium hydroxide are examples of suitable quaternary ammonium hydroxides. It has been found that smaller amounts of quaternary ammonium hydroxides than of the inorganic hydroxides are required in order to efiect the same change in the fibers\of the hose. Quaternary ammonium hydroxides have a greater effect on cellulose than does sodium hydroxide, even to the point of dissolving cellulose if usediat sufllciently high concentrations and if allowed to react over long periods of time or at high temperatures.

It must be emphasized that the process of this invention is not the conventional one of sizing fabrics with polymerizable material and subsequently causing polymerization of the latter.- It

involved, the fact remains that the water-recep- 'tivity of the hose is altered advantageously. by

separate saturation with acrylonltrile and a solution of a strong hydroxide and, as such, the facts are independent th theory.

The following examples will serve to illustrate.

. this'invention:

Example 1 5 Sections of a hard, tightly woven cotton fire hose were thoroughly impregnated by immersion .in acrylonitrile. The sections were then freed of excess nitrile and-immersed in a 15% sodium hydroxide solution for diflerent lengths of time at room temperature, after which the caustic was removed from the hose by thorough washing with water. The hose was then dried. Into one end of each section was placed a tightly fitting metal plug. Water was poured into the sections of hose, and the open ends were then closed with metal plugs. Pressure was exerted on the metal plugs, and the pressure at which leakage occurred was recorded. I

. A control sample of untreated hose began to leak as soon as pressure was applied, and, when the pressure had reached eighteen pounds per square inch, the hose leaked through dozens of pores. A treated section of hose which had been immersed in the sodium hydroxide solution for 6.5 hours did not leak until the pressure had reached thirty-six pounds, and then only slightly. A section treated with the sodium hydroxide solution for twenty-four hours did not leak until.

the internal water pressure had exceeded forty pounds per square inch. The" section which had been in contact with sodium hydroxide solution for forty-eight hours did not leak at a pressure of fifty pounds or less, and yet the surface was moist and, hence, fire-resistant due to the diffusion of the water through the fibers.

The increase in leak-proofness improved markedly with the length of time of reaction. This was especially true in cases where the fabric was thick and was made of tightly twisted yarns which retarded the rate of penetration of the reagents. The treated hose had, in addition to its increased water-receptivity, a greater resistance to the bacterial and fungal action which ordinarily causes deterioration of untreated hoses.

Example 2 Sections of a heavy, hard-woven hose were sealed at one end with metal plugs and were then filled with,acrylonitrile. After five minutes, the acrylonitrile' was poured out and was replaced with a 15% solution of sodium hydroxide. The caustic solution was allowed to remain in the various sections for increasing lengths of time, after which it was removed by thorough washing. The sections-of hose were dried and thereafter tested as in Example 1.

The\ control leaked immediately on the application of pressure. The section treated with caustic for-'twenty-four hours did not leak below a pressure of thirty-two pounds. The surface of the hose treated by this method was normal in appearance and feel, whereas the sections treated in Example 1 tended to have a slippery feel.

Example 3 A section of hose made of mixed fibers of linen and cotton was treated and tested as in Example 2. A section which had been treated for twenty-four hours with the caustic was much more resistant to leakage than was the untreated con trol, which in turn leaked less rapidly than the untreated all-cotton hose used in Examples 1 7 cellulosic fibers of a fabric hose are rendered more water-receptive, and the hose becomes more impervious to the leakage of aqueous media, and (55- 'pecially-water, when the hose is treated separatea solution of a strong hydroxide, d thereafter removing the strong hydroxide.

hydroxide, and

2. The process of reducing the porosity of a fabric hose, made at least partially oi. cotton, which comprises treating the hose in separate operations with acrylonitrile and a solution of a strong droxide.

3. The process of claim 1 in which the strong hydroxide is sodium hydroxide.

4. The process of reducing the porosity of cotton fire hose which comprises treating the hose in separate operations with acryionitrile and a solution of a strong hydroxide, and thereafter renoving the strong hydroxide.

" JAMES w. STALLINGS.

thereafter removing, the hy- 

